mfd: Add HI6421 PMIC Core driver

This adds driver to support HiSilicon Hi6421 PMIC. Hi6421 includes multi-
functions, such as regulators, codec, ADCs, Coulomb counter, etc.
This driver includes core APIs _only_.

Drivers for individul components, like voltage regulators, are
implemented in corresponding driver directories and files.

Registers in Hi6421 are memory mapped, so using regmap-mmio API.

Signed-off-by: Guodong Xu <guodong.xu@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

3 files changed, 127 insertions, 0 deletions

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 049796a28215..609b7a2144d6 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -210,6 +210,19 @@ config MFD_MC13XXX_I2C
         help
           Select this if your MC13xxx is connected via an I2C bus.
 
+config MFD_HI6421_PMIC
+        tristate "HiSilicon Hi6421 PMU/Codec IC"
+        depends on OF
+        select MFD_CORE
+        select REGMAP_MMIO
+        help
+          Add support for HiSilicon Hi6421 PMIC. Hi6421 includes multi-
+          functions, such as regulators, RTC, codec, Coulomb counter, etc.
+          This driver includes core APIs _only_. You have to select
+          individul components like voltage regulators under corresponding
+          menus in order to enable them.
+          We communicate with the Hi6421 via memory-mapped I/O.
+
 config HTC_EGPIO
         bool "HTC EGPIO support"
         depends on GPIOLIB && ARM
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index bd111213bd58..1d11a247abbb 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -172,6 +172,7 @@ obj-$(CONFIG_MFD_AS3722)	+= as3722.o
 obj-$(CONFIG_MFD_STW481X)       += stw481x.o
 obj-$(CONFIG_MFD_IPAQ_MICRO)    += ipaq-micro.o
 obj-$(CONFIG_MFD_MENF21BMC)     += menf21bmc.o
+obj-$(CONFIG_MFD_HI6421_PMIC)   += hi6421-pmic-core.o
 
 intel-soc-pmic-objs             := intel_soc_pmic_core.o intel_soc_pmic_crc.o
 obj-$(CONFIG_INTEL_SOC_PMIC)    += intel-soc-pmic.o
diff --git a/drivers/mfd/hi6421-pmic-core.c b/drivers/mfd/hi6421-pmic-core.c
new file mode 100644
index 000000000000..321a2656fd00
--- /dev/null
+++ b/drivers/mfd/hi6421-pmic-core.c
@@ -0,0 +1,113 @@
+/*
+ * Device driver for Hi6421 IC
+ *
+ * Copyright (c) <2011-2014> HiSilicon Technologies Co., Ltd.
+ *              http://www.hisilicon.com
+ * Copyright (c) <2013-2014> Linaro Ltd.
+ *              http://www.linaro.org
+ *
+ * Author: Guodong Xu <guodong.xu@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/mfd/core.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/mfd/hi6421-pmic.h>
+
+static const struct mfd_cell hi6421_devs[] = {
+        { .name = "hi6421-regulator", },
+};
+
+static struct regmap_config hi6421_regmap_config = {
+        .reg_bits = 32,
+        .reg_stride = 4,
+        .val_bits = 8,
+        .max_register = HI6421_REG_TO_BUS_ADDR(HI6421_REG_MAX),
+};
+
+static int hi6421_pmic_probe(struct platform_device *pdev)
+{
+        struct hi6421_pmic *pmic;
+        struct resource *res;
+        void __iomem *base;
+        int ret;
+
+        pmic = devm_kzalloc(&pdev->dev, sizeof(*pmic), GFP_KERNEL);
+        if (!pmic)
+                return -ENOMEM;
+
+        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        base = devm_ioremap_resource(&pdev->dev, res);
+        if (IS_ERR(base))
+                return PTR_ERR(base);
+
+        pmic->regmap = devm_regmap_init_mmio_clk(&pdev->dev, NULL, base,
+                                                 &hi6421_regmap_config);
+        if (IS_ERR(pmic->regmap)) {
+                dev_err(&pdev->dev,
+                        "regmap init failed: %ld\n", PTR_ERR(pmic->regmap));
+                return PTR_ERR(pmic->regmap);
+        }
+
+        /* set over-current protection debounce 8ms */
+        regmap_update_bits(pmic->regmap, HI6421_OCP_DEB_CTRL_REG,
+                                (HI6421_OCP_DEB_SEL_MASK
+                                 | HI6421_OCP_EN_DEBOUNCE_MASK
+                                 | HI6421_OCP_AUTO_STOP_MASK),
+                                (HI6421_OCP_DEB_SEL_8MS
+                                 | HI6421_OCP_EN_DEBOUNCE_ENABLE));
+
+        platform_set_drvdata(pdev, pmic);
+
+        ret = mfd_add_devices(&pdev->dev, 0, hi6421_devs,
+                        ARRAY_SIZE(hi6421_devs), NULL, 0, NULL);
+        if (ret) {
+                dev_err(&pdev->dev, "add mfd devices failed: %d\n", ret);
+                return ret;
+        }
+
+        return 0;
+}
+
+static int hi6421_pmic_remove(struct platform_device *pdev)
+{
+        mfd_remove_devices(&pdev->dev);
+
+        return 0;
+}
+
+static struct of_device_id of_hi6421_pmic_match_tbl[] = {
+        { .compatible = "hisilicon,hi6421-pmic", },
+        { },
+};
+
+static struct platform_driver hi6421_pmic_driver = {
+        .driver = {
+                .name   = "hi6421_pmic",
+                .of_match_table = of_hi6421_pmic_match_tbl,
+        },
+        .probe  = hi6421_pmic_probe,
+        .remove = hi6421_pmic_remove,
+};
+module_platform_driver(hi6421_pmic_driver);
+
+MODULE_AUTHOR("Guodong Xu <guodong.xu@linaro.org>");
+MODULE_DESCRIPTION("Hi6421 PMIC driver");
+MODULE_LICENSE("GPL v2");